1. Field of the Invention
The present invention relates to an electronic device, and more particularly, to a portable electronic device.
2. Description of the Prior Art
Various types of touch input technology are widely used in electronic products, especially portable electronic devices, e.g. mobile phones and tablet PCs. A portable electronic device uses a touch panel as an input interface, such that a user may perform touch operations on the touch panel to input commands, e.g. drag a finger to move a cursor or write words on the touch panel. Also, the touch panel may cooperate with a display to show virtual keys for being selected by the user to input characters and words.
In general, touch panels are categorized into resistive, capacitive, ultrasound, and infrared types, wherein the resistive touch panels are the most popular. The resistive touch panels may be further categorized into 4-wire, 5-wire, 6-wire, and 8-wire touch panels, wherein the 4-wire touch panels have been widely manufactured and applied due to consideration of cost and technology maturity. However, the capacitive touch panel can sense a slight touch, which is more convenient, and the capacitive control panel is hardly worn by finger touch, which leads to stable performance, and longer life in comparison with the resistive touch panel. Thus, the capacitive control panel has gradually replaced the resistive control panel.
A touch panel may include a substrate on which a trace layer, an insulation layer and a flexible printing circuit board (FPC) pattern may be formed. The substrate is made of transparent materials, e.g. glass, but bonding materials formed on a border of the substrate are translucent or colored, such that the substrate may not visually hide the insulation layer and the FPC pattern when the user looks at the touch panel from a side view. To improve an appearance of the touch input device, a conventional technology adds an additional frame onto a housing to cover inner elements which are not desired to be seen by the user, i.e. the insulation layer or the FPC patterns. As a result, the housing is hard to get rid of the frame.
More importantly, the touch panel of the conventional portable electronic devices is composed by two substrates, which is hard to comply with the requirement of thin portable electronic devices. Moreover, the touch panel may include a cover lens to protect the inner circuits and elements, which further increases the thickness of the touch panel as well as the thickness of the portable electronic device.
Therefore, how to design an electronic portable device capable of hiding border traces from being seen by users, and removing thickness issue caused by using the double substrates or the cover lens via the substrate structure has become an important topic in the industry.